Causal interactions of six global threats: Systems are most effectively addressed comprehensively, rather than as separate problems.
Key to the interactions in the diagram:
1 War and weapons can cause global warming. (a) Weapons and armies emit a lot of CO2. (b) The huge expense of weaponry diverts money from changing to carbon--negative technologies.
2 Global warming can cause wars. Farmers who can no longer produce crops may be recruited as warriors.
3 War and weapons can cause famine. (a) Wars keep farmers from producing or marketing food. (b) Nuclear war will cause global famine when soot in stratosphere from burning cities blot out sunshine, turning summer into fall or winter, preventing crops from growing.
4 War and weapons can cause pandemics. (a) Soldiers travel, and have always spread infectious diseases. (b) Pathogens can be deliberately developed for use as weapons against an enemy.
5 War and weapons can cause radiation exposure. Miners, workers, and soldiers come into contact with fissile material, weapons, and depleted uranium.
6 Cyber attacks can cause war and weapons. Future wars will be fought by soldiers sitting at computers, controlling weapons at a distance. Even now it may be possible for a distant hacker to gain control of nuclear missiles and launch them, provoking the attacked country to retaliate.
7 War and weapons can cause cyber threats. One country may prefer to knock out its enemy’s electric grid than to bomb its cities.
8 Global warming can cause famine. Doughts, floods, desertification will make it harder to grow crops or transport food to markets and will create climate refugees living in camps.
9 Cyber threats can exacerbate global warming. Already cyber attacks against banks are claiming about 10% of the profits and interfering with industrial and agricultural supply chains. On a larger scale, such attacks can have catastrophic effects, e.g. if a continent’s electric grid is destroyed.
10 Global warming can cause pandemics. Mosquitoes are now spreading to temperate climates, bringing new diseases such as Zika.
11 Pandemics can cause famine. In a pandemic, quarantines are necessary, keeping people from their normal activities, including the production and marketing of food.
12 Cyber attacks can cause famine. Farmers’ planting schedules are based on centrally held metrics such as soil fertility. Hackers entering fake, incorrect data could lead to failed crops or even famine.